A racket of tennis or badminton includes a loop-shaped frame through which a string is stretched. The frame includes a large number of insertion holes through which the string is inserted at predetermined intervals, and grommets are mounted to the insertion holes.
As the grommet, for example, as disclosed in PLT 1, a grommet is used that includes a plurality of cylindrical portions inserted into the insertion holes and a strip-shaped portion having a backside surface on which the cylindrical portions are continuous. In a state where the string is stretched through the frame, the string is passed through an inner side of the cylindrical portion to be extracted from an inner side of the frame to the outer side of the frame, and the string is folded back along a surface of the strip-shaped portion to be passed through the next cylindrical portion. That is, the string is folded back at an opening position communicated with the cylindrical portion on the surface (an outer surface) of the strip-shaped portion.